The solar industry has seen rapid growth over the past decade, and a major contributing factor has been the surge in solar farms popping up across the globe. A “solar farm,” also known as a photovoltaic power station, typically refers to a massive decentralized solar array meant to supply the electric grid.
The majority of these massive arrays are owned by utilities and are merely another asset for the utility to supply power to properties in their coverage area. However, a broader understanding of solar farms could include other ground mounted solar arrays large enough to supply power for many households. This general concept of a solar farm could be associated with both residential community solar and larger utility-scale solar. In this article we’ll explain the different types of solar farms, how much they cost and how to start one.
Solar farms and community solar
The idea of community solar has taken off in recent years as more homeowners have realized that they can go solar without putting solar panels on their own physical roof. A community solar project—sometimes referred to as a “solar garden” or roofless solar —is a solar power plant whose electricity is shared by more than one household. In most cases, a community solar array is a large ground mount installation that spans one or many acres.
Visually, these solar gardens resemble utility-scale solar farms, but they are often smaller in size. Customers can either purchase a share of a solar garden and own that portion of the overall array or they can lease energy from the solar system and, in a sense, replace their monthly utility payments with monthly community solar payments that are typically at a lower price. You can find community solar projects in your town or state in our Community Solar Marketplace.
How much do solar farms cost?
Solar farms at the utility scale will typically be at least 1 megawatt (MW), which is a power plant capable of supplying some 200 households. Though cost will range based on a number of factors like location and available sunlight hours, top commercial provider First Solar has stated that the cost per watt for solar installations at this scale is somewhere around $1/watt in 2017. Therefore, you can assume that a 1 MW solar farm would cost roughly $1 million to install.
If that value sounds unusually low in comparison to typical costs associated with residential solar ($3 to $4 dollars per watt), it should. The “economies of scale” concept is in full effect with the solar industry.
The largest solar system installed in the world is the Kamuthi Power Plant, which went live last December in India. The 648 MW array was bid at $0.93 per watt and can supply energy to over 150,000 households.
It should be clarified that these gargantuan solar plants are more commonly referred to as “solar farms” than smaller ground mount arrays often see with community solar projects. Solar systems at the scale of the Kamuthi Power Plant are the size of entire towns and thus take on the name “solar farm” to reference the mere size of the install (see image above). The term more commonly used with community solar is “solar gardens” due to the fact that the system could be only a few acres and could even live in someone’s backyard.
Building a solar farm: how does it work?
When considering building a solar farm, whether it be a 50 kW array or a 50 MW array, here are five key questions you should ask:
How many acres do I need for this size of a power plant?
A smaller solar farm may only require a few acres of land whereas a large utility scale solar farm can require hundreds of acres (for reference, the above mentioned Kamuthi Power Plant spans 2,500 acres).
How will electrical connection work?
You’ll need to consider the location of the land and whether or not it’s situated close enough to power lines and electrical panels to feasibly connect your array to the power grid or to a centralized power source.
How will I clean and maintain the plant?
Whether or not the location has water sources or cleaning options will be important in order to maintain the efficiency of so many solar panels that are situated so close to the ground. The Kamuthi Power Plant, for example, is constantly cleaned by a team of solar-powered robots.
How many solar panels will I need?
In order to make sure you’ll be able to meet the expected energy demand with your solar farm, you’ll need to first start with the needed kilowatt hours of energy and work backwards to get a number of panels you’ll need for the array. To calculate this figure, you’ll need to determine the solar panel production ratio for your area to understand how much energy a certain solar panel wattage will provide. Check out our full explanation on how to do this type of calculation.
What’s a good price for my solar installation?
For larger arrays, there will likely be significant discrepancies between quotes from various contractors, so it will be important to get a few bids from different companies. Solar Power World compiles a list of top solar developers each year that can be a helpful starting point.
If you’re in the early stages of considering a residential solar installation, rather than a solar farm, our Solar Calculator can offer a free estimate for what the array might cost, when you could break even on the investment and how much it could save you over time. For those interested in the community solar options in their state, check out our network of Community Solar Providers.